Currently running the mitas army specials i'll admit they make for a interesting ride in these conditions.

One trick I learnt years ago, if it's a old worn road that has the car tracks smoothed off, ride in the rougher raised centre line, it's less liable to collecting water and the imperfections allow the tyre to contact a little better.

I agree with the XT use the engine braking to your advantage, just remember it has a lot of torque so go gentle.

A mixed blessing I found is the 21" front on the R and Z, the gyroscopic effect will help keep the front stable but needs a bit more care on the turns, if you loose it then it has a better chance to self correct, also stay loose on the bars and relax the arms, but grip the tank with your legs.

If you are going to hit a small ice patch that's unavoidable, so long as you have time to react. relax, neutral throttle, neutral body position, pick the shortest straightest route.

And probably most important thing I've found, stay warm. you can concentrate on the road surface far better if your not distracted by being cold.